U.S. Pat. Nos. 5,773,647 and 5,866,536, as well as International Application WO 00/59863 disclose pharmaceutical compositions for the oral delivery of calcitonin using modified amino acids as oral delivery agents. Said documents are incorporated herein by reference. Oral delivery agents disclosed include N-(5-chlorosalicyloyl)8-aminocaprylic acid (5-CNAC), N-10-[2-hydroxybenzoyl]aminodecanoic acid (SNAD) and N-(8-[2-hydroxybenzoyl]amino)caprylic acid (SNAC), disodium salts and hydrates and solvates thereof.